Posture chair



R. A. CRAMER POSTURE CHAIR Ailg. 22, 1944.

.Filed June 29, 1942 2 Sheets-Sheet 1 54 fa ACra Gttorneq Aug. 22, 1944." R. A. CRAMER 2,356,507

POSTURE CHAIR Filed June 29, 1942 2 Shecs-Sheet 2 Zmnentor fag/l drama Witch-rm Patented Aug. 22, 1944 UNITED STATES PATENT OFFICE POSTURE CHAIR Roy A. Cramer, Kansas City, Mo.

Application June 29, 1942, Serial No. 449,009

4 Claims.

This invention relates to oiflce chairs of that class having a vertically-adjustable and rotatable seat and a back-rest carried thereby, said backrest being independently vertically adjustable relative to the seat.

One of the objects of the invention is to provide a construction having a plurality of legs, a spider mounted rigidly on the legs and engaging the customary post depending from the seat in such manner that the post can be raised through but is not rotatable relative to the spider.

Another object is to provide a spider for receiving the upper ends of the legs and making provision for clamping action upon opposite sides of the legs to hold them firmly against lateral play or movement.

A further object is to provide a spider with top and bottom plates separated by spacers which brace the plates against bending at or near their outer edges; the spaces being provided with inwardly-converging spreader arms to fit flatly against the proximate sides of adjacent legs.

- A still further object of the invention is to provide the plates of the spider with stiff but bendable tongues to project between adjacent legs for spreading the spacer arms and causing them to clamp firmly against the adjacent sides of adjacent legs.

Another object is to provide a s mple, strong and inexpensive bracket mechanism for securing a back-rest adjustably on a stiff spring metal bar carried by the seat, and for permitting the backrest to rock back and forth on a horizontal axis below the horizontal center line of the back-rest against resistance offered by springs tending to hold the back-rest in a substantially vertical position. I have found that by thus pivoting the back-rest, it will better accommodate itself to the occupant without gouging or punching him in the small of the back.

With the above objects in view and others as will hereinafter appear, the invention consists in certain novel and useful features of construction and organization of parts as hereinafter described and claimed; and in order that it may be fully understood, reference is to be had to the accompanying drawings, in which- Figure 1 is a front elevation of a chair embodying the invention.

Figure 2 is a side view of the chair.

Figure 3 is an enlarged horizontal section on the line IIIIII of Figure 1. r

Figure 4 is a horizontal section taken on the line IVIV of Figure 1; the legs of the chair appearing in plan view. a I

sides of the legs, one of the latter being omitted to clearly disclose upstanding flanges on the bottom plate and inturned vertical flanges at the side margins of the spacers for interlocking engagement with the legs.

Figure 8 is a vertical section taken on the line VIII-VIII of Figure 7, with the center tube in side elevation.

Figure 9 is a top view of the bottom plate of the spider disclosed by Figures '7 and 8.

Figure 10 is an enlarged perspective view of one of the spacers of the modified form of spider.

Referring now to the drawings in detail, I is a seat swivelled upon a cylindrical post 2, depending from the conventional bracket 3, secured to the bottom of the seat, and 4 is a stiff metal angle bar adjustable horizontally back and forth on said seat bracket.

Vertically adjustable on said angle bar is a bracket mechanism 5, and pivotally mounted thereon is a back-rest 6. The post 2, has the customary longitudinal groove 1 and vertically spaced sockets S diametrically opposite said groove.

The post extends through a spider, comprising a sleeve 9 swaged inwardly at its opposite ends as at ID and II respectively, and reduced at its middle to provide a narrow internal bearing l2, in vertical alinement with the inner edges of the swaged portions. The bearing I 2 forms in conjunction with the swaged ends of the tube or sleeve 9, spaced guide bearings for permitting vertical adjustment of the post 2 while firmly centering the same against wobble or looseness. The sleeve 9 has welded or otherwise rigidly secured to it in a plane below that of the flange or swaged portion ill, a horizontal plate l3, and a horizontal bottom plate M, fits upon the lower end of the sleeve and is provided with outwardlyprojecting equi-spaced radial arms I5, corresponding in number to the legs l6, preferably of Wood or the like. The legs curve downwardly and outwardly and fit at their inner or upper ends upon the bottom plate l4 and its arms I5.

,and against the underside of the top plate 13,.

the width of the legs preferably corresponding to that of said arms l5. The legs are preferably equipped with casters I! or the like.

The spaces between the legs, where they lie between and against the top and bottom plates preferably exceed the Width of the legs at the perimeters of the plates and are spanned by vertical triangular leg-bracing plate-stiffening segmental spacers l8, and the inwardly converging arms 18a, of which at opposite vertical edges of the spacers and of equal height therewith, bear flatwise against the sides of the inner ends of the legs (Figure 4) and also abut the top and bottom plates l3 and I4. The segmental spacers describe curves conforming to those of the plates but of slightly less radius, and constitute, in conjunction with the latter, a hollow spider of cylindrical form.

The plates l3 and I4 have holes H3 in the vertical planes of the legs, and screws 20 extend through said holes and into the legs to retain the latter in place. The arms l5 fit flatly against the undersides of the legs and have holes receiving screws 2i entering the legs to augment resistance to lateral shifting or vertical rocking of the legs relative to the spider.

To guard against noise due to looseness and play of the legs after long and hard service of the chair, and to secure the spacers, both plates, between the legs, are provided with pairs of intersecting incisions (see Figures 3, 4 and 6), of substantially right-angle form, to provide triangular clamp tongues 23. The tongues, when the spider is completed and mounted on the legs, are bent downwardly from the top plate and upwardly from the bottom plate, to enter the upper and lower ends respectively, of the alined leg-bracing and plate-stiffening spacers for clamping the spacer arms firmly against the interposed legs, and as the legs loosen through long or hard service, the bending of the tongues can be increased to further spread the said arms to take up any slack between them and the legs, without removing the spider from the post.

To hide the top plate from view a circular flanged cap 24, fitting slidingly on the post, rests upon the upper end of the sleeve 9. The cap flange depends far enough to encircle the top plate 53, and short lugs 25 at the lower edge of the cap flange, are bent inwardly to slightly underlie said plate and externally abut the segmental spacers to assist in holding them in place.

The latch means (Figures 1 and 5) for securing the seat at the desired height by engagement with a socket 8, is of conventional type and needs no description, but as it is shown above plate !3, the cap flange is provided with a notch 26, to accommodate that part of the latch means lying between the flang and sleeve 9.

Referring now to the modification of the form of spider, the top plate 33 is provided with a continuous depending marginal flange 34. It is fitted upon and welded or otherwise rigidly secured to a central sleeve 35 adapted to receive a center seatsupporting post of the type shown at I, and there will be provided means, such, for example, as appears on sheet I, to prevent rotation of the post and means to secure the post at the desired height.

Spaced a suitable distance below the plate 33, is a bottom plate 36, provided with a plurality of upstanding flanges 3! in vertical alinement with flange 34 of the top plate, there being spaces of uniform width between the flanges 31; and projecting radially outward from the plate 36 between adjacent flanges, are arms 38 of the same type as arms P5 of the spider of Sheet 1. Fitting against the inner sides of the continuous flange 34 of plate 33, and the spaced flanges 31 of the plate 36, and abutting the top and bottom plates, are spacers 39 of substantially the same size as flanges 31 except as to height, and at the side margins of the spacers are inwardly-projecting narrow flanges 46.

To hold the legs 41 in position, which extend radially into the spider between pairs of the spacers 39, the upper sides of the legs have crossnotches 41a, receiving the depending flange 34 of top plate 33, and the undersides of the legs rest upon the bottom plate and its arms 38. The legs are clamped firmly in position through the use of the ring-nut 42, the sleeve 35 and the top plate 33 and bottom plate 36, the ring-nut being screwed upon the sleeve and engaging the underside of the bottom plate. To further guard against outward movement of the legs, they are provided in their opposite sides with vertical grooves 43, receiving snugly the vertical edge flanges 43 of the spacers, as shown clearly in Figure 7. The cross notches Ma in the upper sides of the legs intersect or merge into the vertical grooves and are engaged by the depending flange 34 of top plate 33, which flange also enters the upper ends of the vertical grooves 43, at the outer sides of the spacers.

The legs, while clamped in place by the ringnut, sleeve and top and bottom plates, as explained, are further secured to the top and bottom plates by screws (not shown in Sheet 2), corresponding to screws 23 and 2|, in Figures 3 and 5. Outward movement of the legs is still further guarded against by the engagement of the vertical flanges 40 of the spacers, with the vertical grooves 43 in the opposite sides of the legs, the spacers being held against outward movement by the depending flange 34 of top plate 33, and the upstanding marginal flanges 37 of bottom plate 36, which flanges do not underlie but stand between the legs, and by fitting against the lower ends of the spacers, cooperate with the continuous flange 34, in holding the spacers and hence the legs, in place.

To assemble the legs in fixed relation to the spider, the latter, lacking the bottom plate, is inverted. The legs, also inverted, are fitted into the spider through the spaces between the spacers. The bottom plate, also in inverted position, is then fitted on sleeve 35 and the spacers, and against the underside of the legs. The ring nut 42 is then screwed upon the sleeve and efiects the clamping of the plates upon the spacers and the legs, and the latter may then be fastened to the bottom plate arms by means of screws 23-2 I, and the top plate is fastened to the legs by screws 20. It is, of course, obvious that the method or steps followed in assembling the legs in proper relation to the spider are merely suggestive and may be varied.

From the above description and drawings it will be apparent that I have produced a construction embodying all of the features of advantage set forth as desirable, and while I have described and illustrated the preferred embodiment, it is to be understood that I reserve the right to all changes within the spirit and scope of the appended claims.

I claim:

1. In a chair having a seat and a post depending therefrom, a series of supporting legs and a spider provided with a catch mechanism for securing the post to the spider at different elevations; the spider comprising a sleeve embracing the post as a slidable bearing therefor, a top plate encircling and rigid with the sleeve and overlying and secured to the legs, a bottom plate encircling the sleeve and secured to the legs, and laterally-spaced means between the legs and plates to stiffen and space the latter, and to bear against opposite sides of the legs between the perimeters of the plates and the said sleeve and a cap covering the upper end of the spider and mounted on the sleeve and fitting around the top plate and having lugs underlying the latter.

2. In a chair having a seat and a post depending therefrom, a series of supporting legs and a spider provided with a catch for securing the post to the spider at difierent elevations; the spider comprising a sleeve embracing the post as a bearing therefor, a top plate encircling and secured to the sleeve and overlying and secured to the legs, a bottom plate encircling the sleeve and secured to the said legs, and laterally-spaced arcuate plates between the legs and the plates to stiifen and space the latter apart, and having inturned vertical flanges to bear against opposite sides of the legs between the perimeters of the plates and the said sleeve, and manually-bendable tongues stamped from the plates and engaging said laterally-spaced flanges for spreading them apart to maintain them tightly pressed against the sides of adjacent legs.

3. In a chair having a seat and a post depending therefrom, a series of supporting legs and a spider provided with a catch for securing the post to the spider at diiierent elevations; the spider comprising a sleeve embracing the post as a bearing therefor, a top plate encircling and secured to the sleeve and overlying and secured to the legs, a bottom plate encircling the sleeve and secured to the said legs, laterally-spaced means between the legs and the plates to stiffen and space the latter apart, and to bear against the opposite sides of the legs between the perimeters of the plates and the said sleeve, and a cap encircling the post and resting upon the upper end of the sleeve; the cap having 3, depending flange encircling the top plate and provided with lugs underlying the top plate and externally engaging said laterally-spaced means.

4. In a chair having a seat and a post depending therefrom, a series of supporting legs extending convergingly inward toward the post, a

vertical spider between the inner ends of the legs,

provided with a catch for securing the post at difierent elevations; the spider comprising a sleeve embracing the post as .a bearing therefor, top and bottom plates encircling the sleeve and secured to the legs, said top plate being secured to said sleeve; leg-spacing plates between the legs and the top and bottom plates and provided at their opposite sides with inwardly-converging arms or flanges fitting against the proximate sides of the adjacent legs, the top and bottom plates having between the vertical planes of adjacent pairs of legs, pairs of V-shape incisions, one branch of each incision extending substantially radially relative to the axis of the sleeve,

and the other branch of each incision intersecting the outer end of the first-named branch, the inner end of the latter and the end of the intersecting branch remote from the intersection with the radial branch, occurring in a plane parallel with the adjacent leg whereby a tongue is pro- Vided susceptible of being bent toward and against the adjacent spacer plate flange in engagement with such leg.

ROY A. CRAMER. 

